"Noise reduction" part 8113 retrofit option?

[TheShipwright]

Reading timangus' post which references "part 8110" for light spring change in this thread.
http://thorncyclesforum.co.uk/index.php?topic=12344.0
I googled "rohloff part 8110" and came across the following PDF
This https://www.rohloff.de/fileadmin/rohloffde/download/preisliste_bestellung/articlelist.en.pdf

It mentions part 8113 which is a retrofit option for hubs with s/n 40000 and below, which reduces noise.

Does anybody have any experience of this or an idea of how it reduces noise?

Thanks